The present invention relates to a thermoelectric power generator unit using thermoelectric elements and to a portable electronic appliance to be driven on the energy thereof and, more particularly, to a thermoelectric power generated timepiece.
Conventionally, there has been disclosed a structure of a thermoelectric type wrist watch using, as an energy source replacing a battery, a thermoelectric element for causing an electromotive force based on a Seebeck effect.
FIG. 2 is a sectional view showing a structure of a conventional thermoelectric power generated timepiece having a thermoelectric element as an energy source.
The thermoelectric power generated timepiece is in a timepiece structure comprising a movement 201, a thermoelectric type generator 202, an electric energy capacitor (not shown), a metal bottom part 203, a frame part 204 formed of a thermally insulating substance, and a metal top part 205. A thermoelectric power generated timepiece as above is disclosed, for example, in Japanese Patent Publication No. 13279. However, practicing has not been made for a thermoelectric power generator unit having a sufficient power generation capability and taking into account size reduction and for a thermoelectric power generated timepiece using such a thermoelectric power generator unit. Also, there has been no disclosure of a concrete structure of such a thermoelectric power generator unit.
The thermoelectric element can produce an electromotive force by providing a temperature difference between a heat absorbing side as a first support member and a heat radiating side as a second support member. The electromotive force increases with increase of the temperature difference. In order to obtain a high electromotive force, there is a need to raise the efficiency of heat absorption from a heat source and the efficiency of heat radiation through the thermoelectric element. This requires an efficient heat conduction path to conduct the heat from the back lid to the thermoelectric element and radiate heat from the thermoelectric element to the case and from the case into ambient air.
However, the thermoelectric element is weak in strength for an external force. In particular, n-type semiconductors and p-type semiconductors are in an elongate columnar form, a plurality of which are arranged standing. Accordingly, if a lateral force or excessive vertical force is applied with respect to a direction of heat transfer through the n-type semiconductor and p-type semiconductor, there is a fear that the thermoelectric element be damaged. Meanwhile, it has been impossible to provide a contact force to the heat absorbing member and heat radiating member into contact with the thermoelectric element in order for increasing thermal conductive efficiency.
Therefore, it is an object of the present invention to prevent against damage to a thermoelectric element due to an external force and improve impact resistance, and also facilitate handling of the thermoelectric element during assembling and obtain a thermal conducting structure good in thermal conductive efficiency.
In order to solve the problem in the prior art that the thermoelectric element is weak in strength and the thermoelectric element is difficult to assemble and handle, the present invention is a unit structure wherein thermoelectric elements are arranged at inside by protecting means having a heat absorbing member and a heat radiating member and fixed on a member on a heat absorbing side or heat radiating side by attaching holding means to connect the thermoelectric elements in series by electrical connection means, preventing fracture of the thermoelectric element due to an external force and realizing a structure good in thermal conductivity. Also, the unit structure can minimize the area of the protecting member and hence effective for thermoelectric element protection and heat loss. The thermoelectric power generator unit is easy to exchange because of screw fixing.
Also, the structure of the thermoelectric power generator unit according to the present invention can be provided directly on the back lid.